I am hoping for someone who can answer this question with greater expertise than my own but here is a link to a recent discussion I had about this with u/Subs-man and on a question of my own u/The_Manchurian recommended "Homosexual Desire in Revolutionary Russia: The Regulation of Sexual and Gender Dissent" and "Bolshevik Sexual Forensics: Diagnosing Sexual Disorder in Clinic and Courtroom, 1917-1939", both by Dan Healey.

As far as I am aware Marx says very little about the subject. But as I said, I am hoping someone more knowledgeable will provide an answer here.